SOLUTION: a circular piece of paper of radius 20 cm is cut in half and each half is made into a hollow cone by joining the straight edges. Find the slant height and the base radius of each c
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Question 980523: a circular piece of paper of radius 20 cm is cut in half and each half is made into a hollow cone by joining the straight edges. Find the slant height and the base radius of each cone Answer by ikleyn(52798) (Show Source):
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The slant height of the cone is equal to the radius of the original circular piece of paper, i.e 20 cm. It is obvious.
Now, let x be the radius of the base of the cone.
Then the length of the circle at the base of the cone is 2*pi*r. From the other side, it is equal to the length of the half-circle of the radius 20 cm.
Thus we have the equation
= .
Hence, x = 10 cm.
Answer. The slant height of the cone is 20 cm. The radius of the base of the cone is 10 cm.
